| title | ISBN-13 | year of publication |
|---|---|---|
| WHY? ANIMALS | 978-1-259-00915-0 | 2013 |
| WHY? DINOSAURS | 978-1-259-00921-1 | 2013 |
| WHY? EVERYDAY SCIENCE | 978-1-259-00918-1 | 2013 |
| WHY? FOOD & NUTRITION | 978-1-259-00919-8 | 2013 |
| WHY? PLANTS | 978-1-259-00916-7 | 2013 |
| WHY? SPORTS SCIENCE | 978-1-259-00920-4 | 2013 |
| WHY? THE EARTH | 978-1-259-00914-3 | 2013 |
| WHY? THE HUMAN BODY | 978-1-259-00913-6 | 2013 |
| WHY? THE UNIVERSE | 978-1-259-00912-9 | 2013 |